1. Field of the Invention
This invention relates to a document editing apparatus, and more particularly a document editing apparatus by which a document can be edited by handwritten inputting of characters.
2. Description of the Related Art
In recent years, a document editing apparatus has been put into practical use by which an electronically produced document can be edited in a similar procedure to editing of a document which is performed using paper and a pen.
A document editing apparatus of the type mentioned includes an inputting apparatus for inputting image data (locus data) such as a pen and a pen inputting tablet, and the contents of a manual operation of the inputting apparatus by a user are provided as a set of dots or a set of vectors. Then, the inputted locus data is displayed as an image on a display screen provided on the document editing apparatus and stored into a memory in the document editing apparatus.
The locus data stored in the memory is converted into a character code or a command using a pattern recognition technique, and editing according to a result of the conversion (result of recognition) is performed for a document. It is to be noted that a method wherein several commands (editing operations) are allocated to symbols of particular shapes in advance and deletion of a character, insertion of line feeding or designation of a range is performed by hand-written inputting of one of the symbols is called "gesture recognition".
In this manner, with a document editing apparatus which allows hand-written character inputting, editing of a document is performed in such a procedure as hand-written inputting by a user, pattern recognition of the hand-written inputted information and editing according to a result of the recognition. However, the timings at which various processing steps are performed are different among different apparatus.
For example, with the document editing apparatus "Windows for Pen", if no inputting occurs within a fixed period of time after a user manually writes a character or a gesture on a character inputting field of the apparatus, then pattern recognition is performed by the apparatus. Then, after the recognition is completed, a process according to a result of the recognition, for example, a process of inserting a recognized character string to the cursor position, is performed. (See, for example, NEC Windows for Pen 1.1 Users Guide, p.39).
Meanwhile, with another system described in "A Prototype of a Document Preparation System through Handwriting Employing Lazy Recognition Scheme", Meeting for the Study of Human Interface of the Information Processing Society of Japan, Vol. 43, No. 4, character recognition is performed at a point of time when inputting of a document is all completed or when a user makes a declaration of the intention, and editing according to a result of the recognition is performed.
Although a document editing apparatus on which editing of a document can be performed by hand-written inputting is constructed such that it can be manually operated in a similar procedure as in editing of a document performed using paper and a pen, for example, where the document processing apparatus is of the type wherein editing of a document is performed if no inputting occurs within a fixed period of time after hand-written inputting comes to an end such as the "Windows for Pen", it some times occurs that, while the user is reading the document, the document being read is scrolled on the screen, which deteriorates the efficiency of the editing operation.
The problem Just described will be described in more detail with reference to FIGS. 14 and 15. FIG. 14 illustrates an example of information displayed on the screen of a document editing apparatus immediately after hand-written inputting is performed, and FIG. 15 illustrates information displayed on the screen when a fixed interval of time elapses after the condition shown in FIG. 14 is reached. In the following description, it is assumed that the document editing apparatus is in a mode in which a hand-written inputted character string is inserted to a position forwardly of the cursor position (the portion indicated by a framework in FIG. 14: the position of "h" of "have" on the second line).
In FIG. 14, a user hand writes the character string "and an operation" in order to amend the character sequence "perform character inputting" to another sequence "perform character inputting and an operation". In this instance, the user will perform, after hand-written inputting is performed, elaboration of a succeeding sentence. However, the document editing apparatus executes, independently of the elaboration operation, an inserting operation of the character string "and an operation" after lapse of a predetermined interval of time after the last handwritten inputting is performed.
Consequently, for example, it sometimes occurs that, while the user reads the portion "beginner" shown underlined in FIG. 14, the contents of the screen are rewritten to those shown in FIG. 15. If such re-writing occurs, then the user may miss the reading portion, and may need to re-read the contents beginning with the top of the sentence, which disturbs the document elaboration operation.
Meanwhile, where the document editing apparatus is constructed such that actual editing processing for a document is performed at a point of time when inputting is all completed such as the "Hand Written Manuscript Production Prototype System by the Delay Recognition System" mentioned hereinabove, in order for a user to confirm that editing has been performed in accordance with the user's intention, the user must review the entire amended portion of the document after actual editing processing is completed. On the other hand, where the document editing apparatus is constructed otherwise such that editing processing is executed at a point of time when a user makes a declaration of some intention of it, there is a problem in that a greater number of processing steps are required for the user as compared with the document editing apparatus of the type on which editing of a document is performed if no inputting occurs within a fixed period of time after hand-written inputting comes to an end.